The following two causes are common: 1. Inflammation of the ipsilateral tooth, such as apical infection or caries, which causes irritating pain when biting, leading to implication pain in the ipsilateral ear. 2. Inflammation of the ear canal or middle ear, which can also lead to pain when the muscles of the biting teeth are stretched. If it is caused by dental reasons, you can use cephalosporin anti-inflammatory drugs symptomatically, combined with metronidazole orally, after the inflammation subsides, then choose the next step of treatment. If otitis media or otitis externa is the cause, in addition to antibiotics, local anti-inflammatory ear drops, such as Telbital ear drops, can be used topically, and microwave physical therapy can also be done to promote the absorption of inflammation.